This invention relates in general to a shelving unit and more particularly to the structural beams in the shelving unit. Several products are similar to this product in that they rely on beams affixed to posts to form a rigid shell that in turn supports shelf members. Examples of such prior art are illustrated in the following U.S. Pat. Nos. 5,553,549 and 5,749,481.
Similar frameworks are typically provided with four vertical corner posts and a plurality of horizontal members. For example, U.S. Pat. No. 5,553,549 issued to Nilsson discloses a framework for a shelving unit comprising horizontal members, a plurality of vertical posts, and a locking attachment for connecting the horizontal members to the vertical posts. One disadvantage of this prior art design is that the horizontal support members do not provide enough load bearing capabilities. A further result of this is a poor utilization of material. The material gauge or thickness is higher than necessary and the strength to material weight ratio could be improved which may result in a lower cost per unit of capacity.
U.S. Pat. No. 5,749,481 issued to Miller utilizes a storage rack and a structural beam to maximize the strength of the beam construction. However, the storage rack and structural beam of this patent are very large. Its size assumes a consumer will have an excess of space to house the rack. The storage rack utilizes a structural member to ensure that decking members and pallets will be adequately supported. While the rack has greater strength capabilities, it is very large in size and in weight. The structural beams are connected to the support columns or posts by removeable attachment pins. Specifically, each beam is provided with an upright connector plate with holes for receiving a pin which is then inserted through a selected hole in the vertical column or post. Another disadvantage of this prior art design is that there are a multiplicity of components required for assembly including the aforementioned pins as well as pliers or screwdrivers. Furthermore, it is possible for the nuts and bolts to become loosened over time, thereby resulting in potential instability of the shelving assembly.
Previous structural beams have been used in similar shelving units. An example is a beam model that had a profile of an “L” shape. The beam simply had a flange that came off perpendicular to the top of the beam. Although there are other differences between this prior art and the present invention such as the shape of apertures on the vertical posts, the crux of this prior art is the cross section of the beam profile. The shelving unit containing this beam is an adequate shelving unit. However, this beam does not have a large load bearing capacity. The overall strength and capacity may be substantially improved. Namely, it is possible to provide greater rigidity against horizontal deflection of the beam and maintain the depth of the unit by providing additional rigidity against deflection.